It is safe enable NTFS compression for a STU (NBU 6.0 MP7)

Hi all:

One client have problems with the SL-500. So we are in process to enable STU using NBU 6.0 MP7 on windows Media server.

The problems is that they just have 1.5TB for the STU and I was wondering if can be safe enable NTFS compression (to gain some space and don't impact the client) (maybe also change block size) to squeze more data while the SL-500 becomes on-line again. We can choose over windows2003 (32/64bits) or windows 2008 (32/64bits).

So is help about his is really appreciate.

Thanks a lot.

\PD: the actual media server is a windows 2003 but we can migrate if the performance or the advice about NTFS compression need it.